After the great drive of the previous several years to diversify the IT load onto as many UNIX or Windows NT servers as possible, the air is thick with chickens coming home to roost. People are realizing that the management overhead of multiple small servers can outweigh any benefits of low unit cost. A recent big issue, therefore, is "server consolidation", i.e. the merging of workloads from several small servers back onto one big server.

Suppose you have Server X, which is running some kind of workload, and you want to model the effect of adding the workload which is currently supported by Server Y. In principle the modeling is straightforward - you build a baseline model of Server X, make a What-If model with at least two projection points, and create a new workload component to represent the current work on Server Y. (The purpose of the second projection point is to model a CPU upgrade, in the event that the performance at Point 1, where the new workload is added, is unsatisfactory).

You can do this quickly and easily with any good Capacity Planning software. For a more complete explanation of the steps involved when using an analytical modeling product such as Metron's Athene, e-mail techinfo@metron.co.uk